Process for reacting azelaic dihydrazide with oxalic acid



Patented Oct. 28, 1952 PROCESS FOR REACTING AZELAIC DIHY- DRAZIDE WITHOXALIC ACID Samuel B. McFarlane, Jr., and Alfred L. Miller,

Summit, N. J assignors to Celanese Corporation of America, a corporationof Delaware No Drawing. Application April 9, 1949, Serial No. 86,602

2 Claims. 1

This invention relates to the production of novel polymeric compoundsand relates more particularly to an improved process for the productionof novel polymeric compounds having filament-forming properties.

An object of this invention is the provision of an improved process forthe production of polymeric compounds.

Another object of this invention is the production of novelthermoplastic filament-forming polymers suitable for use in theproduction of films, foils, filaments, fibers and like products.

A further object of this invention is the production of filament-formingpolymeric materials of a high degree of stability and free of cyclicgroups in the polymeric chain.

Other objects of this invention will appear from the following detaileddescription.

We have found that valuable thermoplastic nitrogen-containing polymersmay be obtained by reacting an aliphatic, alicyclic, aromatic or aralkyldicarboxylic acid, or their corresponding dicarboxylic acid esters, acidchlorides or anhydrides which yield dicarboxylic acids on hydrolysis,with an aliphatic, alicyclic or aromatic dihydrazide in a neutral orinert organic solvent at polymerization temperatures. As examples ofneutral or inert organic solvents which may be employed in efiectingsaid polymerization reaction, there may be mentioned nitrobenzene,xylenols such as 1,2,4-xy1enol or 1,3,5-xylenol, cresols such asmeta-cresol, dichlorobenzenes such as ortho and para-dichlorobenzene ornitroal kanes such as, for example, Z-nitropropane.

Optimum results are achieved employing a polymerization reactiontemperature of 170 to 190 'C., particularly when nitrobenzene isemployed as the solvent, and continuing the reaction for from about 1 to6 hours, after which period a polymer exhibiting excellent fiber andfilamentforming properties is obtained. These polymers are truepolyhydrazides containing little or no cyclic groups. The aliphaticdicarboxylic acid, or the corresponding anhydride, acid chloride ordiester are preferably reacted with the aliphatic dihydrazide inequimolecular ratio to'obtain polymers of very high molecular weights.An excess of either the dicarboxylic acid or the dihydrazide may beemployed, and in an amount up to about by weight, in order to avoid anyviscosity changes when the polymers are subjected to high temperatures,as in melt spinning.

The dihydrazides and dicarboxylic acids or derivatives thereof yieldinga dicarboxylic acid on hydrolysis which we employ, in accordance withour novel process, may contain either a straight hydrocarbon chainbetween the carboxy or hydrazine groups, 1. e. an alkylene group, or theintermediate hydrocarbon chain may be of a branched chain structure inwhich the hydrogen atoms in one or more of the methylene groups aresubstituted by an alkyl group. These compounds should, of course, befree of reactive groups other than the carboxyl groups or derivativesthereof, and of reactive groups other than the hydrazide groups whichmay interfere with the reaction. Furthermore, we may also employ N-alkyl-substituted dihydrazides. Suitable dihydrazides which we mayemploy in our novel process are, for example, aliphatic dihydrazidessuch as oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide,glutaric dihydrazide, adipic dihydrazide, pimelic dihydrazide, subericdihydrazide, azelaic dihydrazide, a-methyl adipic dihydrazide, ,B-methyladipic dihydrazide, a,;8-dimethyl adipic dihydrazide, ap-dimethyl adipicdihydrazide, and N,N'-dimethyl adipic dihydraaide, alicyclicdihydrazides such as cyclohexane dicarboxylic acid dihydrazide,cyclohexane diacetic acid dihydrazide or cyclohexene dicarboxylic aciddihydrazide, and aromatic dihydrazidcs such as terephthalic aciddihydrazide, isophthalic acid dihydrazide and phthalic acid dihydrazideor an aralkyl dihydrazide such as phenylene diacetic acid dihydrazide.

Various aliphatic, alicyclic or aromatic dicarboxylic acids and theirderivatives, as mentioned above, which yield said acids on hydrolysisare suitable for use in the preparation of said filamerit-formingpolymeric compounds in accordance with our invention. As examples ofsaid compounds, there may be mentioned oxalic acid, dimethyl oxalate,diethyl oxalate and other alkyl esters of oxalic acid, malonic acid,malonic acid anhydride, diethyl malonate, dipropyl malonate, dibutylmalonate, as Well as other alkyl esters, succinic acid, succinic acidanhydride, dimethyl succinate, diethyl succinate, dipropyl succinate,dibutyl succinate and other succinic acid esters, glutaric acid,glutaric acid anhydride, dipropyl 3 4 glutarate, dimethyl glutarate,diethyl glutarate, Example V dibutyl glutarate, etc., adipic acid,adipic anhy- 540 parts by weight (25 mols) of azelaic dride, diethyladipate, dimethyl adipate, dipropyl adipate, dibutyl adipate, pimelicacid, isopimelic acid t y pmelate i E alky} esters 9 of mixed xylenolsand the mixture heated to 200 g and lsopgnehc Subenc C. for six hours: Apolymer is obtained melting aci diet yl su crate, dimet yl su crate,diproat h pyl suberate, dibutyl suberate, or other alkyl W m ylelds goodfibers on melt hydrazide and 470 parts by weight (2.5 mols) of azelaicacid are dissolved in 3000 parts by weight spinn g. esters of suberlcacid, as well as azelaic acid, diethyl azelate, dimethyl azelate,dipropyl aze- 10 p e VI late and dibutyl azelate or other alkyl estersof A mixture of 3554 partstby Weight (0.025 mols) azelaic acid.Alicyclic dicarboxylic acids such as f ethyl nt nd 4355 parts by weight(0.025 cyclohexane dicarboxylic acid or cyclohexane dimols) f ammodihydmzide in 30 parts by weight acetic acid, and aromatic dicarboxylicacids such of nitrobgnzgne is heated to for 3 houm as terephthalic acid,isophthalic acid, phthalic is A pglymer melting t 2g5 290 C and hi h mayacid or phenylene diacetic acid are also suitable. be memspun mexcellent fibe is Obtained Our novel process enables polyhydrazides of aheterogeneous structure to be readily obtained. Emmple Thus, th p ly ipolym rs may h ve h A mixture of 4.355 parts by weight (0.025 mols)formula of adipic d'ihydrazide and 4.706 parts by weight NHNH CA CNHNH(HJB(II, NH-NH-r -DCYNHNH CE c O (I) H H I! wherein each of A, B, D andE may be the same (0.025 mole) of azelaic acid in parts by weight or adifferent divalent alkylene, alicyclic, aroof nitrobenzene is heated at170 C. for 3 hours. matic or aralkyl residue, or any combination Apolymer melting at 300 C. and which may be thereof, depending upon theparticular dihydramelt spuninto excellent fibers is obtained.

Zide and dicarboxylic acid or dicarboxylic acid derivative, or mixtureof dihydrazides and dicar- 30 Example VIII boxylic acids or derivativesthereof, subjected to the polymerization reaction.

In order further to illustrate our invention, but

A mixture of 4=.355 parts by weight (0.025 mols) of adipic dihydrazideand 5.056 parts by weight L m (0.025 mols) of sebacic acid in 30 partsby weight wlthou" being hmlted thereto the following of nitrobenzene isheated to 180 C. for 3 hours.

amples are given: A polymer melting at 295 C. and which may be Example Imelt-spun into excellent fibers is obtained.

5.40 parts by weight (0.025 mols) of azelaic di- E' hydrazide and 3.654parts by Weight of ethyl oxamampze IA late (0.025 mols) are dissolved in30 parts by 40 0f 'pa ywei (0 3) weight of nitrobenzene and the reactionmixture 0f rephthalic acid and 4.355 parts by weight obtained heated at180 C. for three hours. A (0.025 m ls) f ad p d y a d in 80 p s bypolymerization reaction takes place with the forweight of nitrobenzeneis heated to 170 C. for

'mation of a polymer having a melting point of 3 hours- A polymermelting at more than 300 260 C. The polymer is quite stable toward theC. and which may be melt-spun into excellent action of heat and may bemelt-spun into filafibers is obtained. 15133113735 which exhibit a drawof 100 to. 400% at Example X I A mixture of 3.700 parts by weight (0.025mols) Example H of 1,4-cyclohexanedicarboxylic acid and 4.355 3.60 partsby weight (0.025 mols) of succinic diparts by weight (0.025 mols) ofadipic dihydrazide hydrazide and 5.05 parts by Weight of sebacic acid in30 parts by weight of nitrobenzene is heated (0.025 mole) are dissolvedin 30 parts. by weight to 170 C. for 3 hours- A polymer melting at ofnitrobenzene and the reaction mixture heated more than 300 C. which maybe melt-spun into at 175 C. for two and three-quarter hours.Polyexcellent fibers is obtained.

-merization takes place with the formation of a Our novel processwherein a dihydrazide is polymer melting at 300 C. The polymer may bereacted with a dicarboxylic acid enables the remelt-spun and yieldsexcellent fibers which have action to be effected with an excellentdegree of a draw of100 to 400% at 50 C. control so that cyclization issubstantially or even entirely avoided and true polyhydrazides ExampleIII 00 are formed.

It is to be understood that the foregoing detailed description is givenmerely by way of HMS-- oration and that many variations may be made(0.025 mols) of succinic acid in 30 parts by weight of nitrobenzene isheated to 180 C. for 3 hours. g sgg g g departmg from the spmt of our Aig if fig$ 5? j i gg f if be Having described our invention, what wedeme 0 t sire to. secure by Letters Patent is:

1. Process for the production of a polymer, E'mmpze IV which comprisesreacting at a temperature of A mixture of 5A0? parts by weight of.azelaic dito 190 C. azelaic dihydrazide with an equihydrazide (0.025mols) and 3.152 parts by weight molecular quantity of oxalic acid. in areaction of. oxalic acid (0.025 mole) in. 30 parts by weight mediumconsisting of nitrobenzene. of nitrobenzene is heated at C. for 2 hours.2. Process for the production of a polymer, A polymer melting at 265 C.and which may be which comprises reacting azelaic dihydrazide with Amixture of 4.355 parts by weight (0.025 mols) of adipic dihydrazide and2.952 parts by weight readily melt-spun into excellent fibers isobtained. 75 an equimolecular quantity of oxalic acid at a temperatureof about 180 C. in a reaction medium consisting of nitrobenzene.

SAMUEL B. MCFARLANE, JR. ALFRED L. MILLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Number 6 UNITED STATES PATENTS Name Date Moldenhauer et a1. May30, 1944 Prichard. Feb. 26. 1946 FOREIGN PATENTS Country Date FranceDec. 5, 1941 France Aug. 26, 1943

1. PROCESS FOR THE PRODUCTION OF A POLYMER, WHICH COMPRISES REACTING ATA TEMPERATURE OF 170 TO 190* C. AZELAIC DIHYDRAZIDE WITH ANEQUIMOLECULAR QUANTITY OF OXALIC ACID IN A REACTION MEDIUM CONSISTING OFNITROBENZENE.